how to use cell ?

In my case

>> U
U =
  1×2 cell array
    [1×2 double]    [1×2 double]
>> U{1}
ans =
     1     2
>> U{2}
ans =
     2     3
F = { } ;

How can I obtain F like that?

F = { {1     2} {  2     3} }

Answer 1

[Guillaume]

If you're asking how to transform U into your desired F:

F = cellfun(@num2cell, U, 'UniformOuput', false);

would be one way of doing it.

However, making a cell array of scalar numbers (e.g. {1, 2}) is rarely a good idea. It uses a lot more memory and is more complicated to use.

[Mira le]

I want F to be like that F = { {1 2} {2 3}, {2 3 }, {1 2} }

[Guillaume]

You need to explain the starting point and probably explain the reasoning behind your question.

...and make sure you're actually asking the right question since you've now moved the goalpost.

Right now it looks like the answer to your question: "I want F to be like that F = { {1 2} {2 3}, {2 3 }, {1 2} }" is to simply type:

F = { {1 2}, {2 3}, {2 3 }, {1 2} }

in your code. Hopefully, that's not what you're asking.

[Mira le]

I just forgor to make the right F in the first

[Guillaume]

I still have no idea what you're asking since you haven't even explained what we start with and what you're trying to do.